NEWTOWN, Conn. – Police Chief Michael Kehoe has a message for the White House: “Ban assault weapons, restrict those magazines that have so many bullets in them, shore up any loopholes in our criminal background checks,” he said in an exclusive interview with NBC News.

As Vice President Joe Biden prepares to present his gun violence proposals to the White House this week, the residents of Newtown — including first responders and some families of the victims — are speaking out on gun policy for the first time.

Few have a more personal connection to the issue than Kehoe: He was one of the first on the scene at the Sandy Hook Elementary School on Dec. 14 after reports came in of a shooting. He says he’s still haunted by flashbacks of what he witnessed when he entered the school from the rear -- the eerie silence in the hallways, the smell of burnt gunpowder and then the bodies of dead children on the floor of the classrooms.

“I was sickened. I was angry,” he said. “It was something I never could have imagined could have happened in any school in Newtown.”

But as a veteran law enforcement officer, what was most striking to Kehoe was that the gunman, 20-year-old Adam Lanza, had heavier firepower than Kehoe and his officers. The police had Glock pistols with 14-round magazines; Lanza had a Bushmaster assault-style rifle, two handguns and multiple 30-round magazines that allowed him to squeeze off an estimated 150 shots.

Although it’s still not clear if Lanza ever fired at responding officers — Kehoe thinks he took his own life when he heard the police sirens — the disproportionate balance in firepower bothers him.

“We never like to think we’re going to be outgunned in any situation we’re dealing with," he said. “We do a good job of securing dynamite in our society. … (Assault rifles) are another form of dynamite. … I think they should ban them.”

Kehoe’s comments come as a new grassroots group — called Sandy Hook Promise — is planning a news conference Monday in which residents of Newtown and some of the victims’ families plan to call for a “national conversation” on gun violence, mental health and school safety. The goal: to prevent “similar tragedies from ever taking place again.”

But there is far from unanimity about what should be done about guns.

Marie-Claude Duytschaever, the grandmother of 6-year-old Noah Pozner, the youngest victim that day, said she, too, wants a ban on assault rifles.

“Noah had the right to go to school safely,” she said. “He had the right to live, to have a job and a normal life. I think that’s more important than to have a gun that can obliterate a whole room in seconds.”

Sandy Hook Promise group will not call for specific gun control measures at Monday’s press conference and a few have expressed concerns that the White House is moving too rapidly with its proposals — and without seeking input from the families of the victims of Newtown.

The national headquarters of the National Shooting Sports Foundation — the trade association and lobbying arm of gun manufacturers — is just down the road from the Sandy Hook Elementary School. Its representatives met with Biden’s task force last week, and this week it will hold its annual SHOT SHOW in Las Vegas, an event at which major gun makers get to exhibit their wares.

The group didn’t respond to requests for comment. But last week it posted this statement on its website: “Semi-automatic firearms are now the most popular type of firearm in America and are used for a wide variety of legitimate sporting purposes, including hunting, small game control, target shooting and personal defense. They should not be banned.”

It is not clear whether Biden will include a ban on assault weapons in the proposals he submits this week. Any effort to ban the rapid-fire rifles in the United States is expected to face tough opposition in Congress.